Main fixes:

Added explicit casts (e.g. 0U) to integers in order for them to be
compatible with whatever operation they're used in [Rule 10.1]

Force operands of an operator to the same type category [Rule 10.4]

Voided non c-library functions whose return types are not used [Rule 17.7]

Change-Id: I758e7ef6d45dd2edf4cd5580e2af15219246e75c
Signed-off-by: Anthony Zhou <anzhou@nvidia.com>